Not everybody is a gamer. I think most non-gaming people have several hundred GB of personal photos, vacation movies and that sort of things. They definitely need space, but for those people a 1 TB EVO would make no sense, just stick to a WD Green or similar. However, this group of people tend to rely on laptops, and you have a hard time using multiple drives in those, so a large SSD is the way to go if you can afford it and do not want the hassle of external HDDs.I have a 1TB hard drive on my work computer and not even 100GB is used. No games installed but I don't see the storage for games being more than 100GB.
So let's say I use 200GB on a gaming computer, then the 1TB hard drive is a waste. I'm wasting 800GB whereas I could be using a 256GB or 500GB SSD instead.
A 1TB storage drive is unnecessary for 99% of the population. The other 1% probably need the 1TB because all they do is download 1000 movies per month and sit at home and eat junk food all day. But this is not the majority...
Out of all the people I know, I still don't know anyone who has used more than 500GB of storage space on their computer. Sure, I know a person who hordes movies like there's no tomorrow, but even then, he doesn't even use 500GB of storage space.
Personally I want as large SSD as possible for professional reasons. I move ~1 TB a day, and I know that sticking my files on an SSD makes my postprocessing 3 times faster, so there is some real productivity gains to be made in my case.